中国海洋水色遥感器瑞利散射定标研究

Studing the calibration of China's ocean color sensors using Rayleigh scattering

水色遥感是海洋环境监测的主要技术手段之一。对于任何海洋水色遥感器来说,监测其在轨期间的定标系数变化是非常重要的,否则无法得到精确的定量产品。以我国"HY-1B"卫星水色遥感器为研究对象,开展了基于大洋水体上空的瑞利散射定标方法研究,利用通过对SeaWiFS数据叶绿素、离水辐亮度和气溶胶产品进行分析,选择了符合条件的7个海区实施大气瑞利散射定标,根据2010年12月份选定的4个区域定标结果得到不同海区/不同时间获得的定标系数一致性较好,CH1至CH6的定标系数标准差分布在0.9%～2.1%的范围内,因此瑞利散射定标是有效的非现场定标方法,具有较高的定标精度,其总误差在4.09%。

Ocean color remote sensing is an important technical method for marine environment monitoring. It is vital to monitor the ehange of the calibration coefficients of the sensors related to their status in producing precise quantitative remote sensing products for all ocean color sensors. Focusing on HY-1B satellite-borne ocean color sensor, absolute calibration over Rayleigh scattering was developed with clear ocean areas. Seven zones were se lected by analyzing chlorophyll concentration, water-leaving radiance and aerosol data derived from SeaWiFS measurements. It shows that the calibration coefficients made over different areas at different time are quite consistent. The standard deviations are between 0. 9 % and 2.1% for all visible bands. It can be concluded that the calibration over Rayleigh scattering is an efficient method independent of iwsitu measurements for the absolute calibration of optical sensors from 4 areas selected in December 2010. This method can provide calibration coefficients with4.09 % maximal error.